Can I install a Dashcam in my car?
If you install a tiny camera on a side of your windscreen and record constantly with no help from the driver, and the camera do not obscure your vision when driving, it is LEGAL.
The video can be used as evidence for accidents/incidents in a trial, and it would be very helpful if all cars would have one, then we could see the accident from different points of view and see who was the responsible easily.
Nowadays there are many devices to film in public places, you have to take care what you do with the video you are recording. If you decided to publish on internet you could have problems if any of the persons who you have filmed, do not want to be published on the website. We have the example of google which have taken photos in everywhere, but it can not show people faces
Here you can read a new about a sentence where it is legal to film police when they are working as a public employees: